The hardware page for a standard servo states that it's roughly 2-3kg/cm @ 5 volts

It depends what kind of servo attachement you're using. As @Rich already stated, the Standard Servo's can hold around 2-3kg/cm if you're powering them at 5 Volts.

This means that if you have an attachement that stretches out 1cm from the output shaft, it can hold 2-3kg. If your attachement is 5cm, it can hold 2/5 to 3/5kg

i don't understand the kg / cm look i want to make my robot mostly metallic so i wanted to know if the servo have the ability to pull it up i want to make a humanoid robot so the servo in the leg and arm will it have to raise them up or it can't ?

KG/CM is kilograms per centemeter, as Niek explained.

If it can lift 5Kg/Cm then at 1cm from the spindle of the servo it will be able to lift 5Kg max. The further you get from the pivot point the less weight it can lift.

It's basic physics. For some reason they have always used incorrect measurements since it should technically be newtons but let's ignore that and not confuse everyone

Basically put, the further away from the pivot the more torque is needed to lift the same weight. So, for instance a 5kg/cm rated servo will lift 5kg at 1cm from it's spindle. It wont lift it any further away from it's spindle. As the distance increases the weight it can lift decreases. Another example would be at 5cm from the spindle the maximum weight that can be lifted is 1kg. Or 10cm from the spindle would be 0.5kg.

Have a read of this, it should explain it for you. Unfortunately I'm pushed for time so that's probably the best bet for now. If you're still at a loss I will attempt to simplify it later.

The standard servos are no longer distributed with the future kits. All servos will be a new metal geared heavy duty. Specs soon

@dj sures that's a good news i'm glad that i heared that can i know if there is a way to deliver the ez-robot kits to egypt and how much it will cost me and how much is the revolution kits ?

@robothacker - The pricing on Revolution kits has not been announced yet. We will be able to deliver to Egypt though so don't worry about that! We can't wait to see some EZ-Robot Revolution Robots roaming around Egypt Make sure you take lots of pictures and post them up!

@alan of course i'm working on great project it will be a humanoid robot but i wanted to add the computer vision feature to it so i'm trying and don't worry about photos there will be a lot i promise

thank you very much all of you